Warning leak and management outcome in aneurysmal subarachnoid hemorrhage

Subarachnoid haemorrhage or traumatic lumbar puncture. Differentiation by cerebrospinal fluid parameters in a multivariable approach

Lumbar puncture (LP) is recommended in patients with thunderclap headache and negative computed tomography to rule out spontaneous subarachnoid haemorrhage (SAH). Blood contamination of cerebrospinal fluid (CSF) due to traumatic LP poses a diagnostic dilemma. Therefore, routine CSF parameters were investigated to distinguish between SAH and a traumatic LP. CSF red blood cell (RBC), white blood cell (WBC) count, total protein, CSF colour and supernatant were used for group comparisons of patients with SAH and 'symptomatic controls'. Due to variable time intervals between bleeding onset and LP in SAH patients in contrast to patients with traumatic LP, where blood contamination of CSF occurs at the time of LP, CSF variables were adjusted for decay in time to allow comparability. Logistic regression analysis identified bloody CSF [odds ratio (OR) 32.6], xanthochromic supernatant [OR 15.5] and WBCadjusted [OR 4.5 (per increase of 100/µl)] as predictors of SAH, while age, sex and CSF total proteinadjusted were no predictors. Optimal cut-point of RBCadjusted (determined at day 1 after bleeding) was > 3667/µl to identify SAH patients with a 97% sensitivity and 94% specificity. Combination of low RBC and clear CSF supernatant was found in none of SAH patients. Combined CSF RBC count and CSF supernatant reliably distinguished traumatic LP from SAH.

Longitudinal ventricular cerebrospinal fluid profile in patients with spontaneous subarachnoid hemorrhage

Background

Spontaneous subarachnoid hemorrhage (SAH) is a severe neurological disease that frequently requires placement of external ventricular drainage (EVD). Cerebrospinal fluid (CSF) obtained via the drain is used to detect potential complications of SAH.

Objective

This study aimed to describe the longitudinal profile of routine CSF parameters in patients with SAH and to identify associations with neurological complications.

Methods

A total of thirty-three patients with spontaneous SAH who required an EVD and had at least three consecutive CSF samples collected over a period of more than 7 days were included in this study.

Results

A median of 6 longitudinally collected CSF samples per patient were available within 1–22 days after SAH onset. Overall, red blood cells (RBC) steadily decreased over time, whereas white blood cells (WBC) and total protein (TP) increased until days 6 and 13, respectively, and decreased thereafter. The estimated decay rates of RBC, WBC, and TP were 28, 22, and 6% per day. Distinct CSF patterns over time were linked to known complications after SAH. Patients with rebleeding showed increased RBC, TP, and phagocytosing cells compared to patients without re-bleeding. For ventriculitis, an elevated cell index with a higher proportion of granulocytes was characteristic. CSF of patients with delayed cerebral ischemia showed increased RBC and WBC compared to patients without DCI. Early CSF WBC and cell index were predictive for the occurrence of DCI and ventriculitis later during the disease course. The amount of daily CSF drainage via EVD had no impact on routine CSF parameters.

Conclusion

Longitudinal CSF characteristics are associated with SAH-related complications.

Vessel-wall MRI in thunderclap headache: A useful tool to answer the riddle?

BACKGROUND

Finding an intracranial aneurysm (IA) during a thunderclap headache (TCH) attack, represents a problem because it is necessary to distinguish whether the aneurysm is responsible for the headache as a warning leak or as an incidental finding. High-Resolution Vessel-Wall (HRVW) MRI sequences have been proposed to assess the stability of the wall, as it permits to detect the presence of aneurysmal wall enhancement (AWE). In fact, AWE has been confirmed due to inflammation, recognizable preceding rupture.Case 1: A 37-year-old woman with a migraine more intense than her usual. A CTA revealed a 10 mm AComA aneurysm without subarachnoid hemorrhage (SAH) and HRVW-MRI excluded AWE. The patient's headache improved, and therefore, the aneurysm was considered an incidental finding, and the headache diagnosed as TCH attack. Subsequently, the aneurysm was surgically clipped, and typical migraine relapsed was reported at follow-up (FU).Case 2: A 67-year-old woman with no history of headaches underwent CTA for an abrupt onset of headache. A 7 mm right carotid-ophthalmic aneurysm with no sign of SAH was discovered. HRVW-MRI demonstrated AWE and thus, a TCH attack for a warning leak of an unstable wall was suspected. Endovascular coiling was immediately performed and at FU any further headache attack was reported.

CONCLUSIONS

HRVW-MRI is useful in case of finding aneurysm as the cause of headaches, particularly the TCH attack. In fact, HRVW-MRI could assess the stability of the aneurysms wall, allowing different patient management and eventually the aneurysmal treatment.

Clinical characteristics associated with sentinel headache in patients with unruptured intracranial aneurysms

OBJECTIVE

Sentinel headache (SH) is considered as a signal of the impending rupture of an aneurysm. However, it is difficult to diagnose whether the headaches of patients are associated with unstable aneurysms. Therefore, there is some doubt about the importance of headaches in patients with unruptured intracranial aneurysms (UIAs). This study was performed to explore the existence and clinical characteristics of SH associated with aneurysms.

METHODS

Thirty-six patients with a single UIA were collected in this study. Patients were symptomatically categorized into two groups: SH and non-SH. The PHASES scores and patient and aneurysm characteristics were analyzed. Two independent MRI experts who were blinded to the patients' clinical history conducted the analysis of the SWI results.

RESULTS

There were 15 patients with sentinel headache. No significant difference was found in patient's basic information and history. The SH group had a higher PHASES score than the non-SH group (P < 0.05). In univariable analysis, abnormal SWI signals were significantly more frequent in the SH group (P < 0.01) and the inflow angle was significantly lower in the non-SH group (P < 0.05). In multivariable analysis, abnormal signals in SWI were an independent factor associated with SH (P < 0.01).

CONCLUSIONS

SH exists in patients with UIAs and may indicate a high risk of aneurysm rupture. Abnormal signals on SWI may serve as a clinical feature to identify aneurysm-related SH and be helpful for the formulation of therapeutic strategy. Aneurysm geometry may also be related to SH but need further studies in the future.

Severe Aneurysmal Subarachnoid Hemorrhage after Warning Headache during Pregnancy: A Case Report

BACKGROUND

Aneurysmal subarachnoid hemorrhage is a rare but important cause of maternal death during pregnancy.

CASE DESCRIPTION

A 34-year-old primigravida (31 weeks of pregnancy) with acute headache but no neurological deficits or neck stiffness was prescribed medication and returned home. Four weeks later she presented with severe headache and consciousness disturbance. She was admitted to our hospital, where she fell into a deep coma. Brain CT and three-dimensional CT angiography showed subarachnoid hemorrhage and a 5-mm right internal carotid-posterior communicating artery aneurysm. Fetal heart rate was 60 beats per minute. Emergent cesarean section and surgical clipping were performed. Intraoperative examination revealed that the aneurysm originated at the right posterior communicating artery. There were no postoperative neurological focal deficits. On postoperative day 13 she developed delayed cerebral ischemia of the right temporo-parieto-occipital lobe. She was discharged home 36 days after surgery with left hemianopsia. The infant was free of complications and was discharged at age 17 days.

CONCLUSIONS

A pregnant woman with severe headache should undergo brain CT or magnetic resonance imaging to rule out subarachnoid hemorrhage.

Quantitative Susceptibility Mapping and Vessel Wall Imaging as Screening Tools to Detect Microbleed in Sentinel Headache

Background: MR-quantitative susceptibility mapping (QSM) can identify microbleeds (MBs) in intracranial aneurysm (IA) wall associated with sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited, due to associated skull base bonny and air artifact. MR-vessel wall imaging (VWI) is not limited by such artifact and therefore could be an alternative to QSM. The purpose of this study was to investigate the correlation between QSM and VWI in detecting MBs and to help develop a diagnostic strategy for SH. Methods: We performed a prospective study of subjects with one or more unruptured IAs in our hospital. All subjects underwent evaluation using 3T-MRI for MR angiography (MRA), QSM, and pre- and post-contrast VWI of the IAs. Presence/absence of MBs detected by QSM was correlated with aneurysm wall enhancement (AWE) on VWI. Results: A total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs evident on the QSM sequence was detected in 12 (23.5%) IAs of 11 subjects. All these subjects had a history of severe headache suggestive of SH. AWE was detected in 22 (43.1%) IAs. Using positive QSM as a surrogate for MBs, the sensitivity, specificity, positive predictive value, and negative predictive value of AWE on VWI for detecting MBs were 91.7%, 71.8%, 50%, and 96.6%, respectively. Conclusions: Positive QSM findings strongly suggested the presence of MBs with SH, whereas, the lack of AWE on VWI can rule it out with a probability of 96.6%. If proven in a larger cohort, combining QSM and VWI could be an adjunctive tool to help diagnose SH, especially in cases with negative or non-diagnostic CT and lumbar puncture.

Prospective Implementation of the Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule

Background and Purpose- The Ottawa subarachnoid hemorrhage (SAH) rule identifies patients with headache requiring no testing for SAH, while the 6-hour computed tomography (CT) rule guides when to forgo a lumbar puncture. Our objectives were to: (1) estimate the clinical impact of the Ottawa SAH rule and the 6-hour-CT rule on testing rates (ie, CT, lumbar puncture, CT angiography); (2) validate the 6-hour-CT rule for SAH when applied prospectively in a new cohort of patients. Methods- We conducted a multicenter prospective before/after implementation study from 2011 to 2016 with 6 months follow-up at 6 tertiary-care Canadian Academic Emergency Departments. Consecutive alert, neurologically intact adults with headache were included. For intervention period, physicians were given a 1-hour lecture, pocket cards, posters were installed, and physicians indicated Ottawa SAH rule criteria when ordering CTs. SAH was defined by blood on CT, xanthochromia in cerebrospinal fluid, or >1×10⁶/L red blood cells in cerebrospinal fluid with aneurysm. Results- We enrolled 3672 patients, 1743 before and 1929 after implementation, including 188 with SAH. Proportions undergoing CT was unchanged (88.0% versus 87.5%; P=0.643). Lumbar puncture use decreased (38.9% versus 25.9%; P<0.0001). Additional testing following CT (ie, lumbar puncture or CT angiography) decreased (51.3% versus 42.2%; P<0.0001). Admissions declined (9.8% versus 7.4%; P=0.011). Mean emergency department stay was unchanged (6.3±4.0 versus 6.4±4.2 hours; P=0.685). The Ottawa SAH rule was 100% (95% CI, 98.1%-100%) sensitive, and the 6-hour-CT rule was 95.5% (95% CI, 89.8-98.5) sensitive for SAH. The 6-hour-CT rule missed 5 SAHs: 1 radiology misread, 2 incidental aneurysms, 1 nonaneurysmal cause, and 1 profoundly anemic patient. Conclusions- The Ottawa SAH rule and the 6-hour-CT rule are highly sensitive and can be used routinely when SAH is considered in patients with headache. Implementing both rules was associated with a meaningful decrease in testing and admissions to hospital.

Delayed cerebral ischaemia in patients with aneurysmal subarachnoid haemorrhage: Functional outcome and long-term mortality

INTRODUCTION

Delayed cerebral ischaemia (DCI) is one of the most frequent complications of aneurysmal subarachnoid haemorrhage (aSAH). The purpose of the present retrospective cohort study of patients with aSAH was to identify the association between DCI, functional outcome and 4-year mortality.

METHODS

Patients admitted to the Neurointensive Care Unit at Rigshospitalet, Copenhagen, with aSAH from 1 January 2010, through 31 December 2013 were registered. Patients were categorized into 3 groups: (a) those with DCI, defined as either a decline in consciousness or focal neurological deficits lasting ≥1 hour without any other detectable cause, (b) those without DCI, or (c) those who were unassessable for DCI. Functional neurological outcome after 6 months, as measured by the modified Rankin Scale (mRS), was dichotomized into good (mRS 0-2) and poor (mRS 3-6). Kaplan-Meier survival curves were constructed, and incidence risk rates were calculated both to determine the association between DCI and mortality.

RESULTS

Four hundred ninety-two cases of aSAH were recorded in the study period. DCI occurred in 23% of all patients, corresponding to 33% of assessable patients. Patients without DCI had the best functional outcome (mRS) compared to patients with DCI and patients who were unassessable; furthermore, the latter had worse outcomes than patients with DCI. Patients diagnosed with DCI had significantly higher mortality than those without DCI, even ignoring the first 14 days after admission.

CONCLUSION

DCI may be associated with both short- and long-term morbidity and mortality in patients with aSAH.

On Aneurysmal Rupture and Rerupture

A warning leak is a curious phenomenon attributed to cerebral aneurysms. Once the leak occurs, it has been postulated it could lead to a more catastrophic rebleeding. The designation "warning leak" trickled into neurosurgery vocabulary as early as the 1950s. The phenomenon has been poorly understood and characterized, but its presence spurs emergency physicians and neurointensivists to take action to secure the aneurysm. Rapid treatment of a recently discovered aneurysm is now commonplace, but it has not always been so. Antifibrinolytic agents spawned particular interest in the late 1970s, when many neurosurgeons postponed surgery after a recent hemorrhage. This historical vignette reviews the early views on aneurysmal rupture, rerupture, and the role of fibrinolysis.

Initial misdiagnosis of aneurysmal subarachnoid hemorrhage: associating factors and its prognosis

BACKGROUND

Predicting the fate of patients who are given a misdiagnosis of aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. The purpose was to examine factors associated with initial misdiagnosis of aSAH and to investigate the impact of initial misdiagnosis of aSAH on clinical outcomes.

METHODS

Between January 2007 and December 2015, medical records and radiographic data for 3118 consecutive patients with aSAH were reviewed. There were 33 patients who had been documented with an initial misdiagnosis of aSAH, and all met the following criteria: (1) failure to correctly identify aSAH upon initial presentation to health care professionals; and 2) subsequently documented aSAH after the initial misdiagnosis. After applying exclusion criteria, remaining 2898 patients were included in the control group.

RESULTS

The most common cause of the misdiagnosis is failure to detect aSAH on the initial radiographic imaging. Misdiagnosis group showed lower initial Glasgow Coma Scale, better Hunt-Hess grade, and lower Fisher's grade. Logistic regression analysis showed that initial HH grade (OR, 0.216; p = 0.014), initial Fisher's grade (OR, 0.732; p = 0.036), and hospital type during initial contact (OR, 2.266; p = 0.042) were independently associated with misdiagnosis of aSAH.

CONCLUSIONS

Patients with initially good HH grade, lower Fisher's grade, and visiting non-teaching hospital for initial contact were at risk of being misdiagnosed. Misdiagnosis of aSAH in patients with initial good HH grade did affect clinical outcomes negatively. The rebleeding rate was not significantly different between two groups. However, the mortality rate due to rebleeding was higher in MisDx group than in non-MisDx group.

Strictly Limited Orbital Pain as Sentinel Headache of Subarachnoid Hemorrhage

BACKGROUND

The headache preceding an intracranial aneurysm rupture is called a sentinel headache (SH), and it is characterized by a sudden, intense, and persistent headache. As subarachnoid hemorrhage (SAH) often develops within several weeks of SH, its rapid diagnosis and treatment can improve the prognosis.

CASE DESCRIPTION

A 52-year-old woman with migraine in her medical history visited the outpatient clinic due to left orbital pain. There was no neurologic deficit. Although magnetic resonance imaging examination found no SAH, a left internal carotid artery-posterior communicating artery bifurcation aneurysm was detected by magnetic resonance angiography. Ten days after the onset of orbital pain, the patient consulted our hospital for a second opinion. We scheduled an elective clipping because the irregular shape of the aneurysm had a high risk of rupture. On the day before surgery, the aneurysm ruptured and led to SAH. Clipping was performed immediately. The patient was discharged with no neurologic deficit.

CONCLUSION

Clinicians must take into consideration that unilateral orbital pain, though atypical, may be a symptom of SH.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Retrospective review of previous minor leak before major subarachnoid hemorrhage diagnosed by MRI as a predictor of occurrence of symptomatic delayed cerebral ischemia

OBJECTIVE

This study attempted to determine whether a previous minor leak correlated with the occurrence of symptomatic delayed cerebral ischemia (sDCI).

METHODS

The authors retrospectively evaluated sDCI-related clinical features and findings from MRI, including T1-weighted imaging (T1WI)–FLAIR mismatch at the time of admission, in 151 patients admitted with subarachnoid hemorrhage (SAH) within 48 hours of ictus.

RESULTS

The overall incidence of sDCI was 23% (35 of 151 patients). In all subjects, multivariate analysis revealed that World Federation of Neurosurgical Societies Grades II–V, age 70 years or older, presence of rebleeding after admission, a previous minor leak before the major SAH attack as diagnosed by T1WI-FLAIR mismatch, acute infarction on diffusion-weighted imaging, and CT SAH score were significantly associated with occurrence of sDCI. In patients with no previous minor leak before major SAH as diagnosed by T1WI-FLAIR mismatch, the incidence of sDCI was only 7% (7 of 97 patients).

CONCLUSIONS

A previous minor leak before major SAH as diagnosed by T1WI-FLAIR mismatch represents an important sDCI-related factor. When the analysis was restricted to patients with true acute SAH without a previous minor leak diagnosed by T1WI-FLAIR mismatch, the incidence of sDCI was extremely low.

Ultra-Early Angiographic Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

OBJECTIVE

After aneurysmal subarachnoid hemorrhage (aSAH), prognosis is affected heavily by the presence of delayed cerebral ischemia (DCI). There is growing recognition of ultra-early angiographic vasospasm (UEAV) occurring within 48 hours of aSAH; however, its relationship with DCI and ultimately prognosis remains unclear.

METHODS

Various databases limited to the English language through September 2016 were searched systematically. Eligible studies were those comparing UEAV with control non-UEAV outcomes and follow-up. Two independent reviewers evaluated the quality of studies and abstracted the data, with discrepancies resolved by a third. We calculated odds ratios (ORs) and 95% confidence intervals for all outcomes by using random-effects meta-analyses and performed a heterogeneity analysis.

RESULTS

Four comparative studies were selected for analysis. Pooled analysis demonstrated that UEAV compared with no-UEAV was associated with greater proportion of rupture aneurysms sized greater than 12 mm (38.3% vs. 24.3%, P < 0.00001). A significantly greater number of patients with UEAV had ruptured MCA aneurysms compared with patients without UEAV (29.7% vs. 19.9%, P = 0.005). Compared with no-UEAV, patients with UEAV were significantly associated with symptomatic cerebral vasospasm (OR 2.07, P = 0.05) and DCI/infarction (OR 2.52, P = 0.02). A significant association also was found between UEAV and an unfavorable outcome at follow-up (OR 1.64, P = 0.03) and greater mortality (OR 2.65, P < 0.00001).

CONCLUSIONS

UEAV was significantly associated with symptomatic cerebral vasospasm, DCI/infarction, unfavorable outcome at follow-up, and greater mortality. Patients with intracerebral hematoma, intraventricular hemorrhage (Fisher Grade IV), larger ruptured aneurysms >12 mm, and an MCA location were more likely to have UEAV.

Sentinel Headaches in Aneurysmal Subarachnoid Haemorrhage: What is the True Incidence? A Systematic Review

The aim of this systematic review was to determine the incidence of sentinel headache reported by patients with aneurysmal subarachnoid haemorrhage, and whether they are likely to be due to recall bias or to misdiagnosis of a previous haemorrhage. Nine studies of good quality, which reported the number of patients with aneurysmal subarachnoid haemorrhage with a history of sentinel headache, gave rates of 10% to 43%. Two case-control studies, in which the frequency of a history of sentinel headache in patients with aneurysmal subarachnoid haemorrhage was compared with that in controls with non-aneurysmal subarachnoid haemorrhage or with stroke, gave an incidence of 5% (95% confidence interval 0.5, 16) in controls, suggesting that only a small number of apparent sentinel headaches are due to recall bias. Sentinel headaches appear to be a real entity. Their true incidence may vary from near zero to about 40% according to the rate of misdiagnosis in the community under consideration.

Ultra-early angiographic vasospasm associated with delayed cerebral ischemia and infarction following aneurysmal subarachnoid hemorrhage

OBJECTIVE The clinical significance of cerebral ultra-early angiographic vasospasm (UEAV), defined as cerebral arterial narrowing within the first 48 hours of aneurysmal subarachnoid hemorrhage (aSAH), remains poorly characterized. The authors sought to determine its frequency, predictors, and impact on functional outcome. METHODS The authors prospectively studied UEAV in a cohort of 1286 consecutively admitted patients with aSAH between August 1996 and June 2013. Admission clinical, radiographic, and acute clinical course information was documented during patient hospitalization. Functional outcome was assessed at 3 months using the modified Rankin Scale. Logistic regression and Cox proportional hazards models were generated to assess predictors of UEAV and its relationship to delayed cerebral ischemia (DCI) and outcome. Multiple imputation methods were used to address data lost to follow-up. RESULTS The cohort incidence rate of UEAV was 4.6%. Multivariable logistic regression analysis revealed that younger age, sentinel bleed, and poor admission clinical grade were significantly associated with UEAV. Patients with UEAV had a 2-fold increased risk of DCI (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.4-3.9, p = 0.002) and cerebral infarction (OR 2.0, 95% CI 1.0-3.9, p = 0.04), after adjusting for known predictors. Excluding patients who experienced sentinel bleeding did not change this effect. Patients with UEAV also had a significantly higher hazard for DCI in a multivariable model. UEAV was not found to be significantly associated with poor functional outcome (OR 0.8, 95% CI 0.4-1.6, p = 0.5). CONCLUSIONS UEAV may be less frequent than has been reported previously. Patients who exhibit UEAV are at higher risk for refractory DCI that results in cerebral infarction. These patients may benefit from earlier monitoring for signs of DCI and more aggressive treatment. Further study is needed to determine the long-term functional significance of UEAV.

Neuroradiologic Diagnosis of Minor Leak prior to Major SAH: Diagnosis by T1-FLAIR Mismatch

BACKGROUND AND PURPOSE

In major SAH, the only method to diagnose a preceding minor leak is to ascertain the presence of a warning headache by interview; however, poor clinical condition and recall bias can cause inaccuracy. We devised a neuroradiologic method to diagnose previous minor leak in patients with SAH and attempted to determine whether warning (sentinel) headaches were associated with minor leaks before major SAH.

MATERIALS AND METHODS

We retrospectively evaluated 127 patients who were admitted with SAH within 48 hours of ictus. Previous minor leak before major SAH was defined as T1WI-detected clearly bright hyperintense subarachnoid blood accompanied by SAH blood on FLAIR images that was distributed over a larger area than bright hyperintense subarachnoid blood on T1WI (T1-FLAIR mismatch).

RESULTS

The incidence of warning headache before SAH was 11.0% (14 of 127 patients, determined by interview). The incidence of T1-FLAIR mismatch (neuroradiologic diagnosis of minor leak before major SAH) was 33.9% (43 of 127 patients). Of the 14 patients with warning headache, 13 had a minor leak diagnosed by T1-FLAIR mismatch at the time of admission. Variables identified by multivariate analysis as significantly associated with minor leak diagnosed by T1-FLAIR mismatch included 80 years of age or older, rebleeding after admission, intracerebral hemorrhage on CT, and mRS scores of 3-6.

CONCLUSIONS

We conclude that warning headaches diagnosed by interview are not a product of recall bias but are the result of actual leaks from aneurysms.

Recognizing the signs and symptoms of aneurysmal subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating neurologic condition with a high mortality and long term neurological morbidity in 50% of survivors. In addition, SAH commonly affects young patients causing substantial loss of productive life years and resulting in significant long term healthcare costs. Early recognition of the signs and symptoms of SAH is absolutely critical to earlier intervention, and delays in diagnosis can have devastating consequences. To avoid such delays in SAH diagnosis, the medical provider should recognize its signs and symptoms. Neuroimgaging, cerebrospinal fluid examination and angiography (invasive or non-invasive) facilitate early diagnosis of SAH. The purpose of this review is not to provide an exhaustive critique of the available literature, rather, it is to provide an overview that will better enable a provider to recognize and initiate the workup of patients with SAH.

An updated definition of stroke for the 21st century: a statement for healthcare professionals from the American Heart Association/American Stroke Association

Despite the global impact and advances in understanding the pathophysiology of cerebrovascular diseases, the term "stroke" is not consistently defined in clinical practice, in clinical research, or in assessments of the public health. The classic definition is mainly clinical and does not account for advances in science and technology. The Stroke Council of the American Heart Association/American Stroke Association convened a writing group to develop an expert consensus document for an updated definition of stroke for the 21st century. Central nervous system infarction is defined as brain, spinal cord, or retinal cell death attributable to ischemia, based on neuropathological, neuroimaging, and/or clinical evidence of permanent injury. Central nervous system infarction occurs over a clinical spectrum: Ischemic stroke specifically refers to central nervous system infarction accompanied by overt symptoms, while silent infarction by definition causes no known symptoms. Stroke also broadly includes intracerebral hemorrhage and subarachnoid hemorrhage. The updated definition of stroke incorporates clinical and tissue criteria and can be incorporated into practice, research, and assessments of the public health.

[Aneurysmal subarachnoid hemorrhage]

Acute subarachnoid hemorrhage (SAH) is a severe and acute life-threatening cerebrovascular disease. Approximately 80% of all acute non-traumatic SAHs are the result of a ruptured cerebrovascular aneurysm. Despite advances in diagnosis and treatment a high morbidity and mortality still exists. Apart from the primary cerebral damage there are also secondary complications, such as vasospasm, rebleeding, hydrocephalus, cerebral edema or hydrocephalus. For an appropriate therapy an understanding of the extensive pathophysiology, the options in diagnostics and therapy and the complications of the disease are essential. Anesthesiologists are decisively involved in the therapy of the primary and secondary damages and subsequently in the outcome as well. This article provides an overview of the perioperative and intensive care management of patients with SAH.

Diagnostic approach to cerebral aneurysms

Cerebral aneurysms are an important cause of morbidity and mortality due to their causal effect in non-traumatic subarachnoid hemorrhage. Neurosurgical progress in the 20th century helped to improve patient outcomes greatly. In recent years, techniques such as intravascular treatment by coiling and/or stenting have found an additional place in the management of the disease. With the development of less and less invasive surgical and endovascular techniques, there has also been a continuous development in imaging techniques that have led to our current situation where we dispose of CT and MR techniques that can help improve treatment planning greatly. CT is able to detect and together with its adjunct techniques CT angiography and CT perfusion, it can allow us to provide the physicians in charge with a detailed image of the aneurysm, the feeding vessels as well as the status of blood flow to the brain. Angiography has evolved by becoming the standard tool for guidance during decision making for whatever therapy is being envisioned be it endovascular procedures and or surgery and has even progressed more recently due to the development of so-called flat panel technology that now allows to acquire CT-like images during and directly after an intervention. Thus nowadays, the diagnostic and interventional techniques and procedures have become so much entwined as to be considered a whole.

Nontraumatic subarachnoid hemorrhage in the setting of negative cranial computed tomography results: external validation of a clinical and imaging prediction rule

STUDY OBJECTIVE

Clinical variables can reliably exclude a diagnosis of nontraumatic subarachnoid hemorrhage in patients with negative cranial computed tomography (CT) results. We externally validated 2 decision rules with 100% reported sensitivity for a diagnosis of subarachnoid hemorrhage, among patients undergoing lumbar puncture after a negative cranial CT result: (1) clinical rule: presence of any combination of age 40 years and older, neck pain or stiffness, loss of consciousness, or headache onset during exertion; and (2) imaging rule: cranial CT performed within 6 hours of headache onset.

METHODS

This was a matched case-control study of patients presenting to 21 emergency departments between 2000 and 2011. Patients with a diagnosis of subarachnoid hemorrhage as determined by lumbar puncture after a negative cranial CT result were screened for inclusion. A matched control cohort was selected among patients with a diagnosis of headache after negative cranial CT and lumbar puncture results.

RESULTS

Fifty-five cases of subarachnoid hemorrhage meeting inclusion criteria were identified, 34 (62%) of which were attributed to cerebral aneurysms. External validation of the clinical rule demonstrated a sensitivity of 97.1% (95% confidence interval [CI] 88.6% to 99.7%), a specificity of 22.7% (95% CI 16.6% to 29.8%), and a negative likelihood ratio of 0.13 (95% CI 0.03 to 0.61) for a diagnosis of subarachnoid hemorrhage. External validation of the imaging rule revealed that 11 of 55 subarachnoid hemorrhage cases (20%) had negative cranial CT results for tests performed within 6 hours of headache onset.

CONCLUSION

The clinical rule demonstrated useful Bayesian test characteristics when retrospectively validated against this patient cohort. The imaging rule, however, failed to identify 20% of subarachnoid hemorrhage patients with a negative cranial CT result.

Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/american Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A formal literature search of MEDLINE (November 1, 2006, through May 1, 2010) was performed. Data were synthesized with the use of evidence tables. Writing group members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation. The guideline draft was reviewed by 7 expert peer reviewers and by the members of the Stroke Council Leadership and Manuscript Oversight Committees. It is intended that this guideline be fully updated every 3 years.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with aSAH. The focus of the guideline was subdivided into incidence, risk factors, prevention, natural history and outcome, diagnosis, prevention of rebleeding, surgical and endovascular repair of ruptured aneurysms, systems of care, anesthetic management during repair, management of vasospasm and delayed cerebral ischemia, management of hydrocephalus, management of seizures, and management of medical complications.

CONCLUSIONS

aSAH is a serious medical condition in which outcome can be dramatically impacted by early, aggressive, expert care. The guidelines offer a framework for goal-directed treatment of the patient with aSAH.

Risk Profile of Intracranial Aneurysms

Background and Purpose—

Management of asymptomatic unruptured intracranial aneurysms remains controversial, and recent prospective follow-up studies showed that the rupture rate of small aneurysms is very low. These results are inconsistent with the finding that the majority of ruptured aneurysms in patients with subarachnoid hemorrhage are small.

Methods—

A Markov model was constructed to simulate the natural history of intracranial aneurysms. All epidemiological and statistical data obtained from the Portal Site of Official Statistics of Japan (e-Stat) were adjusted to the standardized age distribution. From the selected data of aneurysm formation, the prevalence of unruptured aneurysms was estimated as 1.45% and the incidence of subarachnoid hemorrhage calculated to be 19.7/100 000/year in the whole standardized population.

Results—

The function for rupture rate constant with time was first analyzed. Selected values for annual rupture rates of 0.3%, 0.5%, 0.7%, and 1.0% showed inconsistencies in the relationship between the prevalence of unruptured aneurysm and the incidence of subarachnoid hemorrhage. Next, the function for a short period of high risk followed by a long period of low risk was considered. Annual rupture rates of 0.5%, 0.7%, and 1.0% indicated epidemiological compatibility with additional early rupture rates of 20%, 15%, and 10%, respectively.

Conclusions—

This study suggests that some aneurysms bleed shortly after formation and thus are rarely detected as unruptured aneurysms. Most aneurysms without early rupture remain stable for the remainder of life through some healing process, and prophylactic treatment for incidentally identified small unruptured aneurysms has no rationale.

Can computed tomography angiography of the brain replace lumbar puncture in the evaluation of acute-onset headache after a negative noncontrast cranial computed tomography scan?

OBJECTIVES

The primary goal of evaluation for acute-onset headache is to exclude aneurysmal subarachnoid hemorrhage (SAH). Noncontrast cranial computed tomography (CT), followed by lumbar puncture (LP) if the CT is negative, is the current standard of care. Computed tomography angiography (CTA) of the brain has become more available and more sensitive for the detection of cerebral aneurysms. This study addresses the role of CT/CTA versus CT/LP in the diagnostic workup of acute-onset headache.

METHODS

This article reviews the recent literature for the prevalence of SAH in emergency department (ED) headache patients, the sensitivity of CT for diagnosing acute SAH, and the sensitivity and specificity of CTA for cerebral aneurysms. An equivalence study comparing CT/LP and CT/CTA would require 3,000 + subjects. As an alternative, the authors constructed a mathematical probability model to determine the posttest probability of excluding aneurysmal or arterial venous malformation (AVM) SAH with a CT/CTA strategy.

RESULTS

SAH prevalence in ED headache patients was conservatively estimated at 15%. Representative studies reported CT sensitivity for SAH to be 91% (95% confidence interval [CI] = 82% to 97%) and sensitivity of CTA for aneurysm to be 97.9% (95% CI = 88.9% to 99.9%). Based on these data, the posttest probability of excluding aneurysmal SAH after a negative CT/CTA was 99.43% (95% CI = 98.86% to 99.81%).

CONCLUSIONS

CT followed by CTA can exclude SAH with a greater than 99% posttest probability. In ED patients complaining of acute-onset headache without significant SAH risk factors, CT/CTA may offer a less invasive and more specific diagnostic paradigm. If one chooses to offer LP after CT/CTA, informed consent for LP should put the pretest risk of a missed aneurysmal SAH at less than 1%.

Revised national guidelines for analysis of cerebrospinal fluid for bilirubin in suspected subarachnoid haemorrhage

It is crucially important to detect subarachnoid haemorrhage (SAH) in all patients in whom it has occurred to select patients for angiography and preventative surgery. A computerized tomography (CT) scan is positive in up to 98% of patients with SAH presenting within 12 h, but is positive in only 50% of those presenting within one week. Cerebrospinal fluid (CSF) bilirubin spectrophotometry can be used to determine the need for angiography in those few CT-negative patients in whom clinical suspicion of SAH remains high; it may remain positive up to two weeks after the event. A lumbar puncture (LP) should only be performed >12 h after the onset of presenting symptoms. Whenever possible collect sequential specimens. Always ensure that the least blood-stained CSF sample taken (usually the last) is sent for bilirubin analysis. Protect the CSF from light and avoid vacuum tube transport systems, if possible. Always use spectrophotometry in preference to visual inspection. All CSF specimens are precious and should always be analysed unless insufficient sample is received. Centrifuge the specimen at >2000 rpm for 5 min as soon as possible after receipt in the laboratory. Store the supernatant at 4°C in the dark until analysis. An increase in CSF bilirubin is the key finding, which supports the occurrence of SAH but is not specific for this. In most positive cases, bilirubin will occur with oxyhaemoglobin.

Sentinel Headache and the Risk of Rebleeding After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

The clinical significance of sentinel headaches in patients with subarachnoid hemorrhage (SAH) is still unknown. We investigated whether patients with a sentinel headache (SH) have a higher rate of rebleeding after SAH.

METHODS

An SH was defined as a sudden, severe, unknown headache lasting >1 hour with or without accompanying symptoms, not leading to a diagnosis of SAH in the 4 weeks before the index SAH. Age, sex, smoking status, clinical grade, computed tomography (CT) findings, angiographic findings, placement of an external ventricular drain, and time to aneurysm obliteration were prospectively recorded. All rebleeding events were confirmed by CT. Outcome was assessed at 6 months according to the modified Rankin Scale.

RESULTS

Of 237 consecutive patients with SAH, 41 (17.3%) had an SH. Rebleeding occurred in 23 (9.7%) of all patients. Patients with an SH had a 10-fold increased odds of rebleeding compared with patients without SH. Aneurysm size and the total number of aneurysms were also significantly associated with rebleeding. There were no differences in age, sex, smoking, CT or angiographic findings, external ventricular drain placement, or time to aneurysm obliteration between groups. Patients with rebeeding had a significantly worse outcome. Logistic regression revealed the presence of an SH as an independent risk factor for rebleeding.

CONCLUSIONS

In our study, patients with SAH who had an SH constituted a special group of patients with a 10-fold odds for early rebleeding. The presence of an SH may select candidates for ultraearly aneurysm obliteration or drug treatment.

Computed tomographic angiography for the evaluation of aneurysmal subarachnoid hemorrhage

OBJECTIVES

Computed tomography (CT) followed by lumbar puncture (LP) is currently the criterion standard for diagnosing subarachnoid hemorrhage (SAH) in the emergency department (ED); however, this is based on studies involving a limited number of patients. The authors sought to assess the ability of CT angiography (CTA), a new diagnostic modality, in conjunction with CT/LP to detect SAH.

METHODS

Consecutive patients presenting to the ED with symptoms concerning for SAH were approached. All patients had an intravenous catheter placed and underwent a noncontrast head CT followed by CTA. Patients whose CT did not reveal evidence of SAH or other pathology underwent LP in the ED. CTAs were read within 24 hours by a neuroradiologist blinded to the patient's history.

RESULTS

A total of 131 patients were approached, 116 were enrolled, and 106 completed the study. In six of 116 patients (5.1%), aneurysm was found on CTA with normal CT and positive findings on LP; three had a positive CTA with normal CT and LP findings (one of which had a negative cerebral angiogram), and there was one false-positive CTA. Follow-up of all 131 patients showed no previously undiagnosed intracranial pathology. In this patient population, 4.3% (5/116) were ultimately found to have an SAH and/or aneurysm.

CONCLUSIONS

In this pilot study, CTA was found to be useful in the detection of cerebral aneurysms and may be useful in the diagnosis of aneurysmal SAH. A larger multicenter study would be useful to confirm these results.

Comparison of Magnetic Resonance Imaging Sequences With Computed Tomography to Detect Low-Grade Subarachnoid Hemorrhage

OBJECTIVES

To compare computed tomography (CT) with magnetic resonance imaging (MRI) for the presumptive diagnosis and localization of acute and subacute low-grade subarachnoid hemorrhage (SAH).

METHODS

We consecutively enrolled 45 patients clinically suspected of low-grade SAH, comparing them with a control group. We obtained axial nonenhanced CT scans as well as fluid-attenuated inversion recovery (FLAIR) and T2-weighted gradient echo (T2*) MRI sequences at 1.0 T. Two neuroradiologists scrutinized the presence of blood at 26 different regions in the intracranial subarachnoid space (SAS).

RESULTS

Three of 45 patients had normal CT and MRI scans, and SAH was excluded by lumbar puncture. We demonstrated SAH on CT scans in 28 of 42 (66.6%) patients, T2* sequences in 15 of 42 (35.7%) patients, and FLAIR sequences in 42 of 42 (100%) patients. Fluid-attenuated inversion recovery sequences were superior to CT in 16 of the 26 evaluated regions.

CONCLUSIONS

The FLAIR sequence was superior for presumptive diagnosis and localization of acute and subacute low-grade SAH, representing a potential tool in this setting.

Comparison of prognosis and complications after warning leaks in subarachnoidal hemorrhage--experience with 214 patients following aneurysm clipping

OBJECTIVES

The 'warning leak', a smaller bleeding event from an aneurysm, which sometimes occurs before an acute massive subarachnoidal hemorrhage (SAH), was first described in 1967. The present study was performed to compare the complications and prognosis for 214 patients with and without a warning leak; aneurysm clipping had been performed in all.

METHODS

The interval between the warning headache and the actual SAH was calculated. The following complications were examined: preoperative hemorrhage, intra-operative rupture of the aneurysm, postoperative re-bleeding, symptomatic vasospasm, shunt-requiring hydrocephalus, ventriculitis, postoperative wound infection, and outcome according to the Glasgow Outcome Scale (GOS).

RESULTS

Sixty-seven (31%) out of the 214 patients had a warning leak with a median distance of 11 days before suffering from major SAH. Preoperative angiographic vasospasms occurred more frequently in the group with a warning bleeding (22.4 versus 6.1%; p<0.05), which means that the warning leaks induce vascular reactions similar to SAH. The outcome of both groups after a mean follow-up time of 22 months did not show any difference. But 30 out of the 67 patients with a warning leak were graded H&H III-V at admission to hospital after a major SAH. The overall outcome for patients graded H&H I and II was in 92% favorable, compared with only a 54% favorable outcome for H&H III-V patients. Long-term outcome in the warning leak group was not impaired by angiographically proven vasospasm.

DISCUSSION

To give patients the chance to start their treatment in a better clinical condition it is important to recognize the early warning signs.

Aneurysmal subarachnoid haemorrhage in pregnancy

Although uncommon, aneurysmal subarachnoid haemorrhage (SAH) in pregnancy can be devastating for both mother and baby. It is the leading cause of other indirect maternal death in England and Wales accounting for 60 deaths in the decade 1988-1999. No single obstetric or neurosurgical unit has sufficiently large database or experience in managing this condition in pregnancy. With significant improvements in antenatal care and management of deliveries, non-obstetric causes of maternal death such as aneurysmal subarachnoid haemorrhage are likely to become increasingly significant. The clinical features of aneurysmal subarachnoid haemorrhage closely resemble those of other commoner conditions seen in pregnancy. It is therefore imperative that awareness by obstetricians and other frontline staff is increased so that a high index of suspicion is maintained when pregnant women present with unique headaches. Prompt neurosurgical referral is vital and early involvement of an experienced neuroradiologist essential. It is only when an early diagnosis is made and an aggressive treatment instituted that the bleak case-fatality figure associated with aneurysmal subarachnoid haemorrhage in pregnancy can be improved. This review, by a multidisciplinary and multicenter team, provides a comprehensive update on the epidemiology, aetiology, clinical presentation, diagnosis and the complexities of the multidisciplinary management of this serious and potentially fatal condition when it occurs in pregnancy.

Secondary headache and head pain emergencies

The vast majority of patients presenting to primary care physicians complaining of headache have primary headaches, such as migraine,tension, or cluster. Secondary or organic headaches, however,always need to be considered, because when present they require prompt diagnosis and intervention. Approximately 10%of patients presenting to the emergency department complaining of headache have a secondary headache, and as many as one in three sudden severe headaches in patients presenting to a general practitioner's office can be attributed to an urgent neurologic condition that requires rapid evaluation and management.